What does "service layer" mean in programming?
service layer is one of the most common terms in software development. This guide explains what it means, how it is used in practice, and why it matters, with real examples from the developer world.
Definition
An architectural layer that contains the business logic of an application, sitting between the API controllers and the data access layer. The service layer orchestrates operations: it calls repositories, applies business rules, and returns results. Keeping business logic here — not in controllers or the database — makes code easier to test and maintain.
Example
"The OrderService.placeOrder() method validates inventory, charges the card, and triggers the notification — all the business logic lives in the service layer."
Related terms
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